These days, electronic circuit boards spread widely in terms of size thereof, for example, from small ones for mobile phones and the like to large boards for servers and the like, and it is required to produce these boards most efficiently in the shortest production time. Meanwhile, a mounting apparatus of a robot type is becoming a mainstream as a form of the apparatus, which mounts electronic components by moving a working head for sucking electronic components by an XY-robot.
Hereinafter, an example of a conventional electronic component mounting apparatus will be described with reference to FIG. 5. In the drawing, reference numerals 1, 2 and 3 represent component feeders for taping components; a reference numeral 4 representing a component feeder for tray-stored components; a reference numeral 15 representing a working head with suction nozzles 16 of component holders for holding electronic components, which can be moved by an XY-robot 17 in X and Y-directions; reference numerals 5 and 6 representing recognition cameras for picking-up images of suction postures of electronic components held by the working head 15 before electronic components are mounted onto a circuit board; a reference numeral 8 representing a loader for carrying in an electronic circuit board 11 into a component mounting work zone; and a reference numeral 9 representing a circuit board transfer and hold unit comprising support rails 9a and 9b for supporting an electronic circuit board 12, which is configured so that one support rail 9b moves to a position 10 to fit the size of the largest electronic circuit board 12 to be handled. A reference numeral 13 represents an unloader for carrying out the electronic circuit board 11 from within the component mounting work zone.
The operation at the conventional electronic component mounting machine 50 constructed as above will be depicted. The electronic circuit board 11 is supported via the loader 8 by support rails 9a and 9b. The working head 15 sucks electronic components through the operation of the XY-robot 17 from the component feeder 1 for taping components by the component suction nozzles 16 installed to the working head 15. Then, the working head 15 moves to above the recognition camera 5 along a route indicated by A, so that the suction postures of electronic components held by the suction nozzles 16 are imaged by the recognition camera 5 and measured. After position corrections of the sucked electronic components are calculated on a basis of the result of the measurement, the sucked and recognized components are mounted while being positionally corrected, onto the electronic circuit board 12 by the movement of the working head 15.
Component feeders for electronic components are installed also behind the component mounting work zone of the mounting apparatus 50, as denoted by reference numerals 3 and 4. Electronic components sucked by the suction nozzles 16 from the component feeder 3 for taping components or from the component feeder 4 with tray-stored components are imaged alike by the recognition camera 6, and are mounted on the electronic circuit board 12 after the suction position postures are recognized and the position corrections are calculated. A movement route of electronic components in this case is indicated by B.
Recently, electronic components vary from a small size to a large size, and also a feed form of electronic components is diverse such as by taping, bulk, stick and tray. The electronic component mounting apparatus is roughly divided to a cassette type feeder as a feed unit for taping type, bulk type, stick type components, and a tray type feeder. Although many of electronic components can be supplied by the above cassette type feeder, electronic components fed with trays are supplied by the tray type feeder.
In a case where the cassette type component feeder and the tray type component feeder are shared as in the above-described component mounting apparatus 50 shown in FIG. 5, conventionally, the tray type component feeder is installed by utilizing a space of the cassette type component feeder. That is, the number of types of components in terms of the feed form such as taping type, bulk type and stick type to be supplied from the cassette type component feeder is reduced, and the tray type component feeder is fitted in the reduced space. As such, the arrangement has the trouble of reducing part of the component types.
In contrast, it can be so devised that a tray type component feed unit 4 is disposed between a cassette type component feeder 7 and a component mounting zone as in a component mounting apparatus 51 shown in FIG. 6, by way of example of installing the tray type component feeder without reducing part of the component types as referred to above. The arrangement eliminates the need of reducing the component types and of greatly increasing an installation area of the component mounting machine. However, in the case of this arrangement in which electronic components are held by suction nozzles 16 of the working head 15 from the cassette type component feeder 7 and moved to the component mounting zone, the held components vary in the thickness by their types, leading to the possibility of an interference between electronic components loaded on the tray type component feed unit 4 present in the movement route, and components sucked by the component suction nozzles 16 if the held components are thick. Thus the component suction nozzles 16 are required to move up for preventing the interference. However, to move up the component suction nozzles 16 to a position with a maximum component thickness taken into account increases an up-down movement distance of the component suction nozzles not only at the time of catching components from the component feeder, but also at the time of mounting components on the circuit board 12. As a result, a time necessary for component mounting becomes long and a mounting cost increases. The mounting time should be shortened for reducing the mounting cost, which necessitates to make movement distances in a horizontal direction and a vertical direction of electronic components shortest in three processes of a suction process for electronic components, a recognition process and a mounting process.